Hyperbolic dimension of Julia sets of meromorphic maps with logarithmic tracts

We prove that for meromorphic maps with logarithmic tracts (e.g. entire or meromorphic maps with a finite number of poles from class $\mathcal B$), the Julia set contains a compact invariant hyperbolic Cantor set of Hausdorff dimension greater than 1. Hence, the hyperbolic dimension of the Julia set is greater than 1.Comment: 7 pages, 1 figur

Analysis of sub-kilobase chromatin topology reveals nano-scale regulatory interactions with variable dependence on cohesin and CTCF

Enhancers and promoters predominantly interact within large-scale topologically associating domains (TADs), which are formed by loop extrusion mediated by cohesin and CTCF. However, it is unclear whether complex chromatin structures exist at sub-kilobase-scale and to what extent fine-scale regulatory interactions depend on loop extrusion. To address these questions, we present an MNase-based chromosome conformation capture (3C) approach, which has enabled us to generate the most detailed local interaction data to date (20 bp resolution) and precisely investigate the effects of cohesin and CTCF depletion on chromatin architecture. Our data reveal that cis-regulatory elements have distinct internal nano-scale structures, within which local insulation is dependent on CTCF, but which are independent of cohesin. In contrast, we find that depletion of cohesin causes a subtle reduction in longer-range enhancer-promoter interactions and that CTCF depletion can cause rewiring of regulatory contacts. Together, our data show that loop extrusion is not essential for enhancer-promoter interactions, but contributes to their robustness and specificity and to precise regulation of gene expression

Intergenerational ties across borders: a typology of the relationships between Polish migrants in the Netherlands and their ageing parents

The question of how intergenerational relationships are maintained when family members reside in different countries has been gaining scholarly attention. However, those studies focus mostly on the so-called old migrant groups. The focus on the‘new migrants’from Central and Eastern Europe is still scarce. In this paper, we examine the transnational ties between Polish migrants in the Netherlands and their parents living in Poland. To identify types of transnational ties, we performed a latent class analysis using data on 970 men and women from the Families of Poles in the Netherlands (FPN) study. Following earlier studies on adult child–parent relationships in transnational context, we combined information on upward and downward emotional support,upward financial and practical support and frequency of contact (face-to-face and via communication technologies) and commitment to norms of filial obligation. Three types of transnational child–parent relationships were distinguished: harmonious, detached and obligatory. Multinomial regression analyses showed that background characteristics of the adult children and their parents rather than the time elapsed since arrival in the Netherlands accounted for variability in relationship type. The relatively high probability of face-to-face contacts even in detached ties is characteristic of the strong commitment to family life among people of Polish descent

Codebook of the families of Poles in the Netherlands (FPN) survey

Background of the survey The release of formal restrictions on the free movement of Central and Eastern Europeans that started with the end of the Cold War and the eastward enlargement of the European Union in the 2000s have led to new migration flows in Europe. Not surprisingly, the number of surveys carried out among migrants from former communist countries has increased significantly in recent years. These surveys, however, tend to focus on topics such as migration and job history, structural and socio-cultural integration in the host country, bonds with the country of origin or family formation and intermarriage. Insofar exchanges with family members are addressed, they tend to be about remittances to and frequency of contact with “the” family in the country that stayed behind. Information about migrants from Central and Eastern Europe regarding exchanges of money, practical support, emotional support with individual family members, background information on the family of origin, espoused family obligations, and marital and parenthood histories and well-being is scarce. The FPN survey was carried out to fill that void. In absolute terms, Poles are the largest group amongst emigrants from the Central and Eastern European countries which accessed the European Union in 2004. Estimates suggest that between 2004 and 2007, at least one million people emigrated from Poland. Among the top destination countries of Poles in Europe are Great Britain, Germany and the Netherlands. In the Netherlands, the annual number of Polish migrants currently entering the country is greater than the number of traditional migrant groups (Turks, Moroccans, Antilleans and Surinamese) taken together. There are more than 160,000 Poles in the Netherlands according to Statistics Netherlands

Decay and coherence of two-photon excited yellow ortho-excitons in Cu2O

Photoluminescence excitation spectroscopy has revealed a novel, highly efficient two-photon excitation method to produce a cold, uniformly distributed high density excitonic gas in bulk cuprous oxide. A study of the time evolution of the density, temperature and chemical potential of the exciton gas shows that the so called quantum saturation effect that prevents Bose-Einstein condensation of the ortho-exciton gas originates from an unfavorable ratio between the cooling and recombination rates. Oscillations observed in the temporal decay of the ortho-excitonic luminescence intensity are discussed in terms of polaritonic beating. We present the semiclassical description of polaritonic oscillations in linear and non-linear optical processes.Comment: 14 pages, 12 figure

What factors influence training opportunities for older workers? Three factorial surveys exploring the attitudes of HR professionals

The core research questions addressed in this paper are: what factors influence HR professionals in deciding whether to approve training proposals for older workers? What kind of training are they more likely to recommend for older employees and in which organizational contexts? We administered three factorial surveys to 66 HR professionals in Italy. Participants made specific training decisions based on profiles of hypothetical older workers. Multilevel analyses indicated that access to training decreases strongly with age, while highly-skilled older employees with low absenteeism rates are more likely to enjoy training opportunities. In addition, older workers displaying positive performance are more likely to receive training than older workers who perform poorly, suggesting that training late in working life may serve as a reward for good performance rather than as a means of enhancing productivity. The older the HR professional evaluating training proposals, the higher the probability that older workers will be recommended for training. keywords: training; older workers; HR professionals; factorial survey; multilevel model

Codebook of the families of Poles in the Netherlands (FPN) survey

Background of the survey The release of formal restrictions on the free movement of Central and Eastern Europeans that started with the end of the Cold War and the eastward enlargement of the European Union in the 2000s have led to new migration flows in Europe. Not surprisingly, the number of surveys carried out among migrants from former communist countries has increased significantly in recent years. These surveys, however, tend to focus on topics such as migration and job history, structural and socio-cultural integration in the host country, bonds with the country of origin or family formation and intermarriage. Insofar exchanges with family members are addressed, they tend to be about remittances to and frequency of contact with “the” family in the country that stayed behind. Information about migrants from Central and Eastern Europe regarding exchanges of money, practical support, emotional support with individual family members, background information on the family of origin, espoused family obligations, and marital and parenthood histories and well-being is scarce. The FPN survey was carried out to fill that void. In absolute terms, Poles are the largest group amongst emigrants from the Central and Eastern European countries which accessed the European Union in 2004. Estimates suggest that between 2004 and 2007, at least one million people emigrated from Poland. Among the top destination countries of Poles in Europe are Great Britain, Germany and the Netherlands. In the Netherlands, the annual number of Polish migrants currently entering the country is greater than the number of traditional migrant groups (Turks, Moroccans, Antilleans and Surinamese) taken together. There are more than 160,000 Poles in the Netherlands according to Statistics Netherlands

Disorder and transport in cuprates: weak localization and magnetic contributions

We report resistivity measurements in underdoped YBa$_{2}$Cu$_{3}$O$_{6.6}$and overdoped Tl$_{2}$Ba$_{2}$CuO$_{6+x}$ single crystals in which the concentration of defects in the CuO$_{2}$ planes is controlled by electron irradiation. Low $T$ upturns of the resistivity are observed in both cases for large defect content. In the Tl compound the decrease of conductivity scales as expected from weak localization theory. On the contrary in YBa$_{2}$Cu$_{3}$O$_{6.6}$ the much larger low T contribution to the resistivity is proportional to the defect content and might then be associated to a Kondo like spin flip scattering term. This would be consistent with the results on the magnetic properties induced by spinless defects.Comment: latex rullier1.tex, 5 files, 4 pages [SPEC-S01/003], submitted to Phys. Rev. Let